nutrients Review Health Effects of Phenolic Compounds Found in Extra-Virgin Olive Oil, By-Products, and Leaf of Olea europaea L. Annalisa Romani 1,*, Francesca Ieri 1, Silvia Urciuoli 1, Annalisa Noce 2,* , Giulia Marrone 2,3 , Chiara Nediani 4 and Roberta Bernini 5 1 PHYTOLAB (Pharmaceutical, Cosmetic, Food Supplement, Technology and Analysis)-DiSIA, University of Florence, Via U. Schiff, 6, 50019 Sesto Fiorentino, Italy 2 UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy 3 PhD School of Applied Medical, Surgical Sciences, University of Rome Tor Vergata, via Montpellier 1, 00133 Rome, Italy 4 Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Viale Morgagni 50, 50134 Florence, Italy 5 Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy * Correspondence: annalisa.romani@unifi.it (A.R.);
[email protected] (A.N.); Tel.: +39-055-457377 (A.R.); +39-06-20902188 (A.N.); Fax: +39-055-2751525 (A.R.); +39-06-20902096 (A.N.) Received: 14 July 2019; Accepted: 28 July 2019; Published: 1 August 2019 Abstract: Olea europaea L. fruit is a peculiar vegetal matrix containing high levels of fatty acids (98–99% of the total weight of extra-virgin olive oil, EVOO) and low quantities (1–2%) of phenolics, phytosterols, tocopherols, and squalene. Among these minor components, phenolics are relevant molecules for human health. This review is focused on their beneficial activity, in particular of hydroxytyrosol (HT), oleuropein (OLE), oleocanthal (OLC), and lignans found in EVOO, olive oil by-products and leaves.